Transcript for Authorities investigating why bus carrying high school band fell down ravine

tonight to the deadly bus crash in Alabama. A high school band traveling back home from Disney world to Houston. Police say the driver of the charter bus was killed when the bus veered off interstate 10 there, plunging down a 50-foot ravine. There are multiple injuries tonight, and hete's ABC's Steve osunsa osunsami. I'm going to need some help. We got a full charter bus, multiple, multiple injuries. Reporter: Police and fire who raced to the scene are still trying to figure out tonight why the driver of this tour bus lost control. Add screaming children to this image of tossed pillows and stuffed animals, and this is what they saw. We need some blankets and some gloves. Anything warm. We're getting hypothermia setting in. Reporter: The bus was on the way home to Texas, carrying the channelview high school band, seen here. They had just finished a trip to Disney world, when police say their driver ran over a median and fell 50 feet down a ravine on I-10 near the alabama/florida state line. The driver, seen here, was killed. 37 people, most of them students, had to be rushed to the closest hospitals. Some had to be physically cut out of the bus. Didn't know exactly how many, many two or three that had to be cut out. Reporter: Our station in Houston was there when one of the students called home. Some students were stuck under seats, some were on top of other students. Reporter: Federal investigators have a team looking into this tonight. The tour bus operator says that their driver, who died here, was a long-time employee and that they're cooperating with authorities. David? Steve osunsami again tonight.

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